Rotary Head Extruder, Method of Extrusion and Extruded Products

ABSTRACT

An improved rotary head extruder incorporates an auger system comprising more than one auger to create asymmetrical, substantially cylindrical extruded products having a density within the range of about 3.0 to about 6.0 lbs./cu ft. A wide variety of fine particles such as flour and powder can be successfully introduced into and conveyed within a rotary head extruder to the die assembly, where the materials are cooked to form hard, dense extruded collets with randomly asymmetrical shapes. A transition piece at the downstream end of the augers allows for continuous, uniform flow to the die assembly, where cooking takes place. Using the equipment described, raw materials other than the typically used corn meal are produced, while maintaining the desired bulk density, texture, and crunch of random extruded products.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. Ser. No. 14/538,532filed Nov. 11, 2014, the disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND

1. Technical Field

The present invention generally relates to an improved rotary headextruder for the incorporation of ingredients that are otherwisedifficult to include within certain rotary extruded collets, referred tothe industry as random collets.

2. Description of Related Art

In the formation of random collet products, inclusion of componentsother than substantially uniform corn meal (i.e., of similar particlesize) or refined meals has proven difficult because of the limitationsof the rotary head extruder. FIG. 1 depicts the well-liked variety ofcorn collets known as random corn collets 2, which are produced by arotary head extruder. Random corn collets 2 comprise unique, twisted(“random”) shapes and protrusions and a highly desirable crunchy texturethat can only be produced with a rotary head extruder. It is a generallyaccepted fact in the industry that these kinds of extruders cannothandle flour-like or non-refined granular materials. As such, extruderformulations for random collets comprise only corn grits or corn meal,and water, to create the collets 2 of FIG. 1. While it may be possibleto incorporate some amounts of other ingredients to slightly modify thedirect expanded products, to date, these amounts are not large enough tosignificantly vary the varieties or tastes of random collet products.Moreover, introduction of small granular materials such as flour orpowder into a continuous random extrusion line typically causes blockageand halts production. Thus, there is a need for a rotary head extrudercapable of handling additional formulations on a continuous basis formass production. In particular, the introduction of ingredients otherthan corn meal into a rotary head extruder while mimicking the appealingcharacteristics of the random corn collet 2 is highly desirable; namely,taste, appearance, density, and mouthfeel (or texture). Such non-cornbased random collet products should emulate the organoleptic properties,including taste and texture, of the conventionally-produced corn-basedshelf-stable and ready-to-eat random collet.

SUMMARY

An improved rotary head extruder replaces the typically used singleauger with more than one auger for continued production and highthroughput rates of random extruded products. More than one screw orauger is encased within a single barrel of the rotary head extruder. Atransition piece downstream from the single barrel ensures that thedelivery to a downstream stator is continuous and uniform, ensuringproper flow of materials introduced into the barrel of the extruder forextrusion. The stator is a stationary plate surrounding an output end ofan interior portion downstream from the single barrel. A rotor, orrotatable plate, is downstream from the stator. The rotatable plate maycomprise a plurality of fingers surrounding a protruding nose conelocated within a die gap, which is between the stator and the rotor.

Extrusion using the rotary die system of a rotary head extruder togetherwith the augers or auger system described herein allows for raw materialcompositions of a variety of fine particle sizes and a wide particlesize distributions to be successfully introduced into and conveyedwithin a rotary head extruder to the die assembly, where the materialsare cooked to form a wide array of random extruded products.

The random extruded products incorporate formulations with variousingredients aside from the typically used corn meal formulations, whilemaintaining the desired bulk density, texture, and crunch of randomextruded collet products made only from corn. Other benefits andadvantages of the present invention will become apparent to one skilledin the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa mode of use, further objectives and advantages thereof, will be bestunderstood by reference to the following detailed description ofillustrative embodiments when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 depicts typical random corn collets as known in the industry.

FIG. 2 depicts a perspective view of a prior art rotary head extruderused in manufacturing collets.

FIG. 3A depicts a close-up view of the main working components of therotary head extruder depicted in FIG. 2.

FIG. 3B depicts a detailed cross-sectional view of the main workingcomponents of the extruder depicted in FIG. 2.

FIG. 4 depicts an exploded view of one embodiment of an improved rotaryhead extruder.

FIG. 5A depicts a top view of one embodiment of an assembled improvedextruder.

FIG. 5B depicts a partially cross-sectional side view of one embodimentof the auger system within an improved rotary head extruder.

FIG. 6A depicts a forward view of the downstream end of the augers inone embodiment described herein.

FIG. 6B depicts a perspective view of the downstream end of oneembodiment of the transition piece.

FIG. 7 depicts another embodiment of an extruder described herein.

FIG. 8 depicts a random extrusion line process incorporating oneembodiment of the extruder described herein.

DETAILED DESCRIPTION

The words and phrases used herein should be understood and interpretedto have a meaning consistent with the understanding of those words andphrases by those skilled in the relevant art. No special definition of aterm or phrase, i.e., a definition that is different from the ordinaryand customary meaning as understood by those skilled in the art, isintended to be implied by consistent usage of the term or phrase herein.To the extent that a term or phrase is intended to have a specialmeaning, i.e., a meaning other than that understood by skilled artisans,such a special definition is expressly set forth in the specification ina definitional manner that directly and unequivocally provides thespecial definition for the term or phrase. The terms “including,”“comprising,” “having,” and variations thereof mean “including but notlimited to,” unless expressly specified otherwise. When used in theappended claims, in original and amended form, the term “comprising” isintended to be inclusive or open-ended and does not exclude anyadditional, unrecited element, method, step or material. The term“consisting of” excludes any element, step or material other than thosespecified in the claim. As used herein, “upstream” and “downstream”refer to locations of objects relative to a location of another objectwith respect to the process direction, where “downstream” refers to thedirection of flow of the food materials to be extruded through the diesystem as described herein.

To better understand the limitations of a rotary head extruder in termsof its typically used corn formulations, and the benefits of theimproved extruder and method described herein, a discussion of theconventional rotary head extruder is helpful.

Rotary head extruders use two round plates to cook and gelatinize cornmeal. One plate is rotating and the other is stationary, producingfriction necessary to produce random collets. These extruders arehigh-shear, high-pressure machines, which generate heat in the form offriction in a relatively short length of time. No barrel heating isapplied in rotary head extruders, as the energy used to cook theextrudate is generated from viscous dissipation of mechanical energy.There is no added water, heating element or cooling element used withina rotary head extruder to control temperatures. Instead, rotary headextruders use friction generated within the round plates (and not in theauger or screw zone) to cook the extrudate. There is no mixing and onlya very limited compression at the auger of a rotary head extruder;specifically, only enough to convey the material in the gap areas withinthe barrel. The shear is instead at the fingers 26 (best shown in FIG.3A), described below. While the auger zone helps transport materials tothe die assembly 10, it cannot mix materials and is a poor conveyer ofmixed materials and of certain ingredients, including very smallingredients such as powders or flours. Instead, the rotary head extruderis limited to refined cereal meal formulations within a narrow range ofparticle size. Anything else often results in flow irregularities alongthe single auger, which turns into blockages in the extruder flow,leading to failure and stoppages of the extruder. In addition, themaximum in-feed throughput capacity is limited to between about 400 toabout 450 lbs/hr.

FIG. 2 illustrates a perspective view of a typical rotary head extruderused for production of the random corn collets 2 depicted in FIG. 1.Pre-moistened cornmeal is gravity-fed through a hopper 4 and into theextruder 6. The rotary head extruder 6 is comprised of two main workingcomponents that give the collets their twisted (“random”), asymmetricalshape: a single screw or auger 8 and a rotary die assembly 10. FIGS. 3Aand 3B illustrate close up and detailed side view images of the two mainworking components 12 of the extruder 6. FIG. 3A depicts a partiallycross-sectional view together with a perspective view of the rotor 20.FIG. 3B depicts the die assembly 10 in cross-sectional view, with theclamp 30, shown in FIG. 3A omitted for clarity. The auger 8 is housed ina cylindrical casing, or barrel 14, and comprises an open feed section16 through which the cornmeal passes, shown in FIG. 3A. It should benoted that the open feed section 16 is slightly turned in FIG. 3A tobetter depict the auger 8. In practice, the hopper feeds into the openfeed section 16 from above. While the barrel 14 is shown to be quiteshort in the figures for clarity purposes, it should be noted that itsportrayal is merely for purposes of depiction and the barrel length isnot drawn to scale. The auger 8 transports and compresses the cornmeal,feeding it to the rotary die assembly 10, where it is plasticized to afluidized state in a glass transition process further described below.

The die assembly 10 contains two brass alloy round plates: a stator 18(with the stationary plate) and a rotor 20 (the rotating plate).Gelatinization of moisturized starchy ingredients takes place inside theconcentric cavity between the two plates 18, 20. The stator 18 is anassembly comprising a stator head section 22 and a round stationarybrass plate 24 that acts as a die through which the gelatinized meltflows. The stationary plate 24 has grooves 48 that aid in thecompression of cornmeal as the stator 18 works together with the rotor20. The rotor 20 is a rotating plate comprising fingers 26 and a nosecone 28. The nose cone 28 channels the cornmeal towards the fingers 26and helps discharge the gelatinized cornmeal through the small gapbetween the rotor 18 and stator 20. The action of the fingers 26 createsthe necessary condition of pressure and heat to achieve plasticizationof the raw materials at approximately 260° F. to 320° F. (127° C. -160°C.). Specifically, the fingers 26 force cornmeal back into the groovesof the stator head 24, causing friction and compression of the cornmealin the gap between the stator 18 and the rotor 20. The brass facing 32on the rotor 20 also helps to create heat and compression. Randomextrusion may thus be characterized by a thermo—mechanicaltransformation of the raw materials brought about by the metal-to-metalinteractions of the die assembly 10.

Several things happen within the die assembly 10 during the randomextrusion process. First, the corn meal is subjected to high shear ratesand pressure that generate most of the heat to cook the corn. Thus,unlike other extruders, most of the cooking takes place in the rotarydie assembly 10 of the rotary head extruder. As stated above, there isno added water or external heat used to control the temperatures withinthis extruder. Second, a rapid pressure loss causes the superheatedwater in the corn mass to turn to steam, puffing the cooked corn as itexits the die assembly. Third, the flow of corn between one rotatingplate 20 and one stationary plate 18 twists the expanding corn leavingit twisted and collapsed in places, resulting in the productcharacteristic shape shown in FIG. 1. The random collets exit the rotaryhead extruder circumferentially outward from the gap between the statorand rotor in a radial path from the center of the fingers in the generaldirection of the straight arrows depicted in FIG. 3A. Cutter bladeswithin a cutter assembly then cut off the collets 2 that result from theexpansion process of the stator-rotor interactions. The process isentirely unique, providing unsystematic, irregularly shaped collets anda texture distinct in its crunchiness, giving somewhat of a homemadeeffect.

Typical prior art corn meal specifications for rotary head extruders,for example, include a particle size distribution where no more than2.5% of the particles can be smaller than 300 microns. The extruderdescribed herein, on the other hand, can successfully process any foodmaterial comprising a particle size distribution comprising more thanabout 5% -10% of the particles smaller than 300 microns. While otherextruders may provide more flexibility in terms of the componentsintroduced therein, only rotary head extruders can perform randomextrusion and create the random collet 2, which upon exit from theextruder, comprises a unique shape and a bulk density ranging frombetween about 3.0 to about 6.0 lbs/cu ft. or more preferably betweenabout 4.0 to about 5.25 lbs./cu ft.

FIG. 4 illustrates an exploded view of the components of an improvedrotary head extruder according to one embodiment of the presentdisclosure. The rotary head extruder comprises a hopper 16, much likethat of the above described rotary head extruder of FIG. 3, throughwhich raw material is passed into a barrel 14. Materials may beintroduced, for example, through a hopper or other funnel device. Withinthe barrel 14 is an auger system comprising more than one auger 42 a,b,also depicted in FIGS. 5A and 5B. A transition piece 40 surrounds an endportion of the augers 42 a,b as best shown in FIGS. 5A and 5B. Thetransition piece 40 fits snugly within the stator head section 22. Inone embodiment, the distance between the external surfaces of the augersto the inner wall of the barrel 14 may range from between about 0.1 mmto about 0.150 mm. In one embodiment, the distance from or openingbetween the exterior surface of the auger and the interior surface ofthe barrel is between about 0.1 to about 0.25 mm. Flight elevates fromthe base of the auger will stop at least about 0.1 mm short of the wallin one embodiment. In an embodiment comprising two augers as shown inFIGS. 5A and 5B, the internal shape of the transition piece 40 presentsan interior flow path 44 to a wider end. In this embodiment, a figureeight shape (shown in FIG. 6A) is shown on the upstream end of aninterior flow path 44. The interior flow path 44 surrounds an end ofeach of the auger 42 a,b the interior shape comprising a figure-eightshape at its base or upstream end, which diverges to a wide circulardownstream end, shown in FIG. 6B. FIG. 7 is a top view of anotherembodiment of an extruder described herein, comprising three screwswithin the barrel 14.

Referring back to FIG. 5A, in one embodiment, the improved rotary headextruder comprises an auger system comprising more than one rotatableauger 42 a, 42 b within a single barrel 14; a transition piece 40 at adownstream end of the rotatable augers 42 a, 42 b, the transition piecehaving a figure eight opening comprising a funnel shaped flow path; anda die assembly 10 comprising or consisting of a stator 18 and a rotor 20with a die gap there between, wherein the stator comprises a stationaryplate 24 surrounding an output end of the transition piece and the rotor20 is a rotatable plate downstream from the stator. The rotatable platecomprising a plurality of fingers 26 surrounding a protruding nose cone28 of the rotatable plate located within the die gap. The single barrel14 is positioned at the end of a shaft controlled by a gear box (notshown) and moveably positioned such that the fingers 26 surrounddownstream ends of the two augers 42 a,b when the extruder is operatedto undergo random extrusion of food materials. It should be noted thatone of the fingers 26 in FIG. 5A is shown only in part so as to betterdepict the nose cone 28. In one embodiment, each of the fingers 26comprise the approximate same length and circumferentially surround thenose cone as well as at least a portion of the downstream ends of thetwo augers 42 a,b.

Each of the two augers 42 a, 42 b is located equidistant to and onopposing sides of the nose cone 28 in one embodiment. The augers 42 a,42 b each comprise a generally cylindrical shank with an outer peripheryproviding a generally helical screw flight configuration, in which theaugers and their respective screw flight configurations are close enoughto intermesh. In one embodiment, the flights are equispaced down thelength of the auger and the diameter of each auger remains consistentthroughout its length. In one embodiment, the augers are positioned soclose to each other that the flight of one auger penetrates the channelof the other auger such that one auger engages the other. That is, inone embodiment, the augers are conjugated, each comprising substantiallyidentical screw flight configurations (i.e., substantially the same oridentical flights in terms of size, number, angle and shape. Conjugatedscrews such as those depicted in FIGS. 5A and 5B fit tightly within thesingle barrel such that the extruded materials pass through the exteriorportion surrounding the collective auger assembly, with little to nopassage in between the augers. In another embodiment, the augers may benon-conjugated to allow for passage all around each auger, so long asthe materials are conveyed towards the die assembly.

In one embodiment, FIGS. 5A and 5B depict the stator 18 and rotor 20with the small die gap there between, which is present during operationof the rotary head extruder. In one embodiment, the die gap is betweenabout 1.25 mm and about 2.54 mm. As described above with the prior artrotary head extruder, cooked and expanded or puffed product will exitthe extruder circumferentially outwards from the die gap. A cuttingsystem will then cut the puffed product into a plurality of snack-sizedportions.

FIG. 5B depicts an interior flow path 44 between the external surfacesof the augers 42 a, 42 b and the walls of the barrel 14, according toone embodiment. The interior flow path 44 encloses an end of two augers42 a, 42 b tightly, forming a figure eight opening (best shown in FIG.6) at the most upstream end of the transition piece 40 towards thebarrel 14. The opening remains constant for a length along a downstreamend of the augers and then funnels out, widening at the exit end of thematerial to be plasticized within the plates. That is, the length of theinterior flow path tapers out in a funnel or conical shape at itsdownstream end in one embodiment. The single barrel 14 houses the twoaugers 42 a,b and extends horizontally along at least half theirconnecting with the transition piece 40 and into the figure 8-shape ofthe flow path 44. While depicted as a separate piece in the figures, thetransition piece 40 may also be an integral part of the stator headsection 22 adjacent to the downstream end of the augers.

Returning to the embodiment of FIGS. 5A and 5B, the stator 18 comprisesa stator head 22 with interior grooves 46 at its outlet end. Forclarity, the grooves 46 of the stator are depicted slightly exaggeratedin length. The interior grooves are preferentially horizontal andcircumferentially spaced around the circular opening. In addition, theinterior grooves 46 should substantially align at their downstream endswith the grooves 48 of the stationary plate 24, which surrounds theoutlet end of the stator head 22. In one embodiment, the stationaryplate 24 comprises or consists of bronze. Other metals may also bepossible so long as friction remains generated in operation. On theupstream end, the interior grooves 46 meet with the downstream end ofthe transition 40 and interior flow path 44, the shape having a slopeextending outwards to meet with the interior grooves 46. Thus, in oneembodiment, the interior flow path 44 comprises a funnel-like shape withits wide end facing the grooves 46 of the stator 18. In one embodiment,the slope of the interior portion of the transition piece 40 begins at alocation behind the augers, or at their downstream tip ends, to meet theinterior grooves 46 of the stator head 22. In one embodiment, the slopeis less than about 75 degrees. In one embodiment, the slope is less thanabout 65 degrees. In one embodiment, the slope is less than about 60degrees. The slope should generally allow for a smooth transition andcontinuous flow of extrudate to the die assembly. In one embodiment, thestator head 22 surrounds the interior portion 44, which provides for aquick transition or short slope end portion between the two auger endsand the stator 18. As perhaps best shown in FIG. 5B, the transitionpiece 40 comprises an upstream portion having a substantially constantor equal thickness along its length. This equivalent upstream stemportion spans at least half the length of the transition piece 40. Thedownstream end of the transition piece 40 comprises a funnel like shape,which slopes out to a mouth with a wider opening at its most downstreamend. The interior portion provides for smooth flow of materials to thedie assembly 10, where they will ultimately be cooked and puffed. Therotor 20 has its own motor drive (not depicted) to control the speed androtation of the rotor during extrusion.

By successfully incorporating the auger system described into anextruder that is still capable of producing random extrusion processes,the transfer of fine or granular materials inside the extruder to therotary die is improved, allowing for positive displacement. The rotaryhead extruder described herein improves the stability of the overallprocess and creates a robust random extrusion system capable ofaccepting a wide variety of raw materials for production of diverserandom collets. During random extrusion, in one embodiment, the augers42 a,b may rotate independently (actuated by separate power sources or atransmission gear) but in the same direction to provide for intermeshingeffects to convey materials between the walls of the single barrel andthe augers. In one embodiment, the augers are connected via a gearbox.As depicted in FIGS. 5A and 5B, in one embodiment, the augers arepositioned horizontally within the single barrel adjacent andsubstantially parallel to one another (i.e., within the same horizontalplane). However, in one embodiment, the augers 42 a,b may also bepositioned vertically, or one on top of the other. In one embodiment,the augers will rotate at speeds of between about 100 to about 500 rpm.In another embodiment, the two augers will rotate at speeds of betweenabout 200 to about 350 rpm. In another one embodiment, the two augerswill rotate at speeds of between about 300 to about 320 rpm.

The auger system is self-wiping and closely intermeshing, transferringmaterials by a positive displacement action by its co-rotatingmechanism, which makes the process more independent of the nature andcomposition of the raw material. Transfer limitations due toconstituents of the raw material difficult to convey such as fiber, oilyparticles, small particulates, or other lubricant-acting components areovercome and conveyance is improved. There remains no added water, noheating element and no cooling element used for the rotary head extruderdescribed herein. The energy used to cook the extrudate is generatedfrom the friction of the die assembly. There are no holes or openings ineither the stator or rotor, and the random collets exit the rotary headextruder circumferentially outward from the gap between the stator androtor.

The extruder described herein can successfully handle continuous randomextrusion of varied materials as well as materials of variable sizes.For example, corn meal having a wide range of particle sizes has beensuccessfully tested, including those that have previously impartedchallenges due to the very different particles sizes of the corn meal.In one embodiment, a food material comprising a particle sizedistribution of between about 200 and about 900 micrometers can be fedinto the rotary head extruder of the present disclosure. In thisembodiment, up to or about 80% by weight of the particle sizedistribution may comprise fine particle size of about 400 micrometers.In other embodiments, the particles may range from about 200 to about1200 micrometers, with optionally about 50% of the particle sizedistribution reaching up to or about 400 micrometers. Additionalembodiments and examples of the raw materials capable of beingsuccessfully extruded are provided below.

In accordance with another aspect of the present disclosure is a methodof random extrusion comprising the steps of feeding raw materials into asingle barrel comprising more than one auger within the single barrel;conveying the raw materials towards a die assembly through the singlebarrel and through a transition piece having a flow path beginningadjacent to a downstream end of the augers and diverging to a wideoutput end, said die assembly comprising a stator, a rotatable platedownstream from the stator, and a die gap between the stator and therotatable plate, wherein the stator comprises a stationary headdownstream of the auger and a stationary plate surrounding the outputend of the transition piece, the wide output end of the transition piecein communication with the stationary plate.

In one embodiment, rotatable plate comprises a plurality of fingerssurrounding a protruding nose cone of the rotatable plate located withinthe die gap. In one embodiment, the raw materials pass through aninterior portion prior to reaching the rotary die assembly.

As depicted in the embodiment of FIGS. 5A and 5B, the nose cone 28 ofthe rotor protrudes inwardly with its tip facing the stator such thatthe nose cone 28 is positioned within the die gap. The single barrelhousing the auger system may be positioned so as to create the die gapbetween the stator and rotor. In some embodiments, the die gap may bebetween about 1.35 to about 1.8 mm. The positioning step places thesingle barrel with its augers such that the fingers of the rotatableplate surround at least a portion of the downstream ends of the augers.The fingers may also surround the downstream ends of the augers in oneembodiment or may be in close proximity to the downstream ends frombetween about 2 to about 6 mm in distance in one embodiment. The feedingstep comprises a feed rate for raw materials of between about 200 toabout 600 lbs/hr. In one embodiment, the feeding step comprises a feedrate of between about 400 to about 550 lbs/hr. In one embodiment, thefeeding step comprises a feed rate of over 450 lbs/hr.

Raw materials comprising a moisture between about 1.0% to about 18% maygenerally be used to form random extruded products in the rotary headextruder described herein. In one embodiment, the method may comprisethe step of pre-moistening or pre-hydrating the raw materials forintroduction into the rotary head extruder. In one embodiment, the rawmaterials comprise an initial moisture content of between about 11% toabout 12.5%. Raw materials may be pre-hydrated to from about 14.5% toabout 18% moisture by weight. In one embodiment, the raw materials arepre-hydrated to about 16.9% in-barrel moisture content by weight. In oneembodiment, the method may comprise the step of pre-mixing rawmaterials, which may include mixing one type of raw material with wateror with other raw materials with water for moistening prior tointroduction into the improved rotary head extruder. In this way,different materials can be moistened to the same approximate moisturelevel, for example.

During extrusion, and perhaps more specifically, the conveying step, theaugers co-rotate and intermesh, whether independent of one another ornot, in the same direction and/or speed, whether clock-wise orcounter-clockwise. In one embodiment comprising two augers, a twin shotgear box may be used to rotate both augers simultaneously, or a singlegear box with one motor moves two shafts. In one embodiment, each augermay comprise its own gear box to co-rotate independent of one another atthe same speed. In one embodiment, the conveying step may comprise anauger speed of about 100 to 400 rpm. Typically, the die gap remainsconstant during extrusion once the single barrel and rotor is positionedto set the gap, with only small adjustments if necessary in the range of+/−0.5 mm. The temperature of the stator head may range from betweenabout 260 to about 320° F. In some embodiments, the rotor speed may beadjusted to from about 250 to about 600 RPM.

The method further comprises the step of expanding the raw materialsinto a food product comprising a bulk density of between about 3.0 and11 lbs./cu ft., most preferably between 3.0 and 6.5 lb./cu ft. In oneembodiment, expanded and puffed food product comprises a bulk density ofbetween about 4.5 and about 5.0 lbs./cu ft. A cutting step may also beused to cut the expanded and puffed food product to a desirable size.

By way of example, FIG. 8 depicts a random extrusion processing lineinto which the rotary head extruder described herein may be introduced.Briefly, as shown in FIG. 8, in a first step of a random extrusion line,a mixer 60 adds moisture as it mixes the raw materials. The mixer may bevertical, as depicted in FIG. 8, or horizontal (not pictured). The rawmaterials are then transferred to a bucket elevator 42, which elevatesthe materials to the hopper 64 of the rotary head extruder. Next,extrusion forms hard dense extruded product utilizing rotating brassplates, as previously discussed above. The product is then conveyed 66to a fines tumbler 68, which removes small fines from the product, priorto dehydration. The product then passes through a vibratory feeder 70 toprovide even feed to a fryer 72, such as a rotary fryer, which decreasesmoisture and adds oil to the extruded product. Next, an additionalvibratory feeder 74 transfers product to a coating tumbler 76, whereinoil, flavor and salt are mixed. The products can then be turned in aflavor drum 57, wherein flavor is applied to the surface of the randomcollets.

It should be noted that while FIG. 8 describes a process for producingfried random corn collets, such illustration is not meant to limit thescope of this embodiment. In one embodiment, the rotary head extruderdescribed herein may be incorporated into a fried corn collet productionline for producing fried corn collets. In one embodiment, the rotaryhead extruder described herein may be incorporated into a baked corncollet production line for producing baked corn collets.

The raw materials suitable for use in extruding with the rotary headextruder described herein consist of minute separate particle free ofagglomeration. That is, the improved extruder can successfully be usedwith unbound, non-agglomerated particles such as flour or powder. In oneembodiment, the raw materials are discrete milled or ground foodproducts of a fine particle size; optionally within the particle sizedistributions described above. As used herein, non-agglomeratedparticles or non-agglomerated food substances refers to milled or groundindividual food materials separate from, and not bound with, other foodmaterials such as to cause an increase in their size.

An extruded collet snack food product resulting from the extrusiondescribed herein comprises a base portion consisting of non-agglomeratedfood substances, said non-agglomerated food substances comprising afirst food material; a bulk density ranging from about 3.0 to about 6.0lbs./cu ft.; and a moisture content of less than about 3%. In oneembodiment, the non-agglomerated food substances comprise a second foodmaterial unlike the first food material. In other words, the second foodmaterial comprises a nutritional composition unlike that of the firstfood material. In one embodiment, the first food material comprisesyellow corn meal or whole grain cornmeal. In some embodiments, thenon-agglomerated food substances comprise one or more of: cereal flour,cornmeal, and legume flour. In one embodiment, the non-agglomerated foodsubstances comprise discrete hydrated milled or ground components,including without limitation flours or powders. In some embodiments, thefirst food material comprises a cornmeal and the second food materialcomprises any flour derived from legumes or tubers. In certainembodiments, the non-agglomerated food substances comprise a third foodmaterial unlike the first and second food materials with regard to itsnutritional composition. A fourth food material unlike the first andsecond food materials is present within the non-agglomerated foodsubstances of the base portion in some embodiments. Any number ofadditional food materials in non-agglomerated form may be present withinthe base portion. The base portion of the collet may comprise, forexample, one or more of: whole grain corn meal, rice, whole grain flour,rice pea, brown rice, wheat, whole wheat, pea, black bean, pinto bean,potato, sorghum, millet, lentils, and other grain legumes or tubers,whether in flour, powder or other granular form.

The invention will now be further elucidated with reference to thefollowing examples, which should be understood to be non-limitative. Itshould be appreciated by those of ordinary skill in the art that thetechniques disclosed in the examples that follow represent onesdiscovered by the inventors to function well in the practice of theinvention and thus, constitute exemplary modes. One of ordinary skill inthe art, when armed with this disclosure, should appreciate that manychanges can be made in the specific embodiments while still obtainingsimilar or like results without departing from the spirit and scope ofthe present invention.

EXAMPLE 1 Whole Grain Blend

A mixture of whole grain cornmeal and yellow corn meal were blended tocreate a whole grain blend for extrusion and formation of whole grainrandom collets. A mixture comprising about 55% whole grain cornmeal andabout 45% standard cornmeal was introduced into a mixer, into which 4-7%water was added. The mixture was mixed to moisten the whole grain blenduntil it achieved a moisture content of about 15-18%. The particle sizedistribution of this particular cornmeal is between 100 and 700 micronswith up to 58% comprising particle size of about 425 microns. Anin-barrel moisture content of about 15.9% was determined. The rotorposition or gap was set to about 1.52 mm, and the stator headtemperature was recorded to be about 146° C. The auger speed wasinitially set to about 228 rpm and the rotor comprised a rotor speed ofabout 500 rpm. Product rate was measured to be about 467 lb/minute, withresulting expanded, puffed product resulting with a bulk density ofabout 4.75 lbs/cu ft.

EXAMPLE 2 Rice Flour Blend 1

A mixture of rice flour, yellow corn meal and yellow pea flour wasblended to create a rice flour blend for extrusion and formation of riceflour random collets. The mixture comprised about 60% rice flour, about30% corn meal, and about 10% yellow pea flour. The mixture wasintroduced into a mixer and 7% water added. The mixture was mixed tomoisten the whole grain blend until it achieved a moisture content ofabout 17.5%. The rotor position or gap was set to about 1.60 mm, and thestator head temperature was recorded to be about 132° C. The auger speedwas initially set to about 275 rpm and the rotor comprised a rotor speedof about 530 rpm. Product rate was measured to be about 400 lb./minute,with resulting expanded, puffed product resulting with a bulk density ofabout 5.5 lbs./cu ft.

EXAMPLE 3 Rice Flour Blend 2

A mixture of rice flour, yellow corn meal and yellow pea flour wasblended to create a rice flour blend for extrusion and formation of riceflour random collets. The mixture comprised about 55% rice flour, 30%whole-grain corn meal, and 15% yellow pea flour. The mixture isintroduced into a mixer and 7% water is added. The mixture was mixed tomoisten the whole grain blend until it achieved a moisture content ofabout 17%. The rotor position or gap was set to about 1.60 mm, and thestator head temperature was recorded to be about 139° C. The auger speedwas initially set to about 275 rpm and the rotor comprised a rotor speedof about 530 rpm. Product rate was measured to be about 390 lb./minute,with resulting expanded, puffed product resulting with a bulk density ofabout 5.2 lbs./cu ft.

All percentages are by weight unless otherwise disclosed. Unlessotherwise specified, all percentages, parts and ratios as used hereinrefer to percentage, part, or ratio by weight of the total. Unlessspecifically set forth herein, the terms “a”, “an”, and “the” are notlimited to one of such elements, but instead mean “at least one,” unlessotherwise specified. The term “about” as used herein refers to theprecise values as indicated as well as to values that are withinstatistical variations or measuring inaccuracies.

The use of any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention. Unless otherwise defined, all technical and scientificterms and abbreviations used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which the inventionpertains.

The method illustratively disclosed herein suitably may be practiced inthe absence of any element that is not specifically disclosed herein. Insome embodiments, the methods described herein may suitably comprise orconsist only of the steps or characteristics disclosed. In other words,the formulations may comprise or consist only of the componentsdisclosed.

While this invention has been particularly shown and described withreference to preferred embodiments, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.The inventors expect skilled artisans to employ such variations asappropriate, and the inventors intend the invention to be practicedotherwise than as specifically described herein. Accordingly, allmodifications and equivalents of the subject matter recited in theclaims appended hereto are included within the scope of the claims aspermitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed unless otherwise indicated herein or otherwise clearlycontradicted by context.

What is claimed is:
 1. A rotary head extruder comprising: an augersystem comprising more than one rotatable auger within a single barreland a transition piece at a downstream end of the auger system; a dieassembly comprising a stator, a rotatable plate, and a die gap betweenthe stator and the rotatable plate, the stator comprising a stator headat the downstream end of the auger system and a stationary platesurrounding an outlet end of the stator head downstream from the singlebarrel, and the rotatable plate downstream from the stationary plate,wherein said transition piece is within the stator head and begins at alocation behind a downstream end of the rotatable auger and diverges toa wider opening in communication with the stationary plate.
 2. Therotary head extruder of claim 1 wherein the die gap is between about1.35 and about 2.54 mm during operation of the extruder.
 3. The rotaryhead extruder of claim 1 wherein the stator head comprises interiorgrooves in communication with the transition piece.
 4. The rotary headextruder of claim 1 wherein the auger system comprises more than twoaugers within a single barrel upstream from the transition piece.
 5. Therotary head extruder of claim 1 wherein the augers rotatesimultaneously.
 6. The rotary head extruder of claim 1 wherein theaugers rotate at speeds of between about 100 to about 500 rpm.
 7. Therotary head extruder of claim 1 wherein the augers are positionedhorizontally within the single barrel.
 8. A method of extrusioncomprising the steps of: feeding raw materials into a single barrel of arotary head extruder, the single barrel comprising more than one augerwithin the single barrel; conveying the raw materials towards a dieassembly through the single barrel and through a transition piece havinga flow path beginning adjacent to a downstream end of the augers anddiverging to a wide output end, said die assembly comprising a stator, arotatable plate downstream from the stator, and a die gap between thestator and the rotatable plate, wherein the stator comprises astationary head downstream of the auger and a stationary platesurrounding the output end of the transition piece, the wide output endof the transition piece in communication with the stationary plate. 9.The method of claim 8 wherein the feeding step comprises a feed rate ofbetween about 200 to about 600 lbs./hr.
 10. The method of claim 8wherein the raw materials comprise an in-barrel moisture content ofbetween about 14% to about 20%.
 11. The method of claim 8 wherein theraw material consists of minute separate particles free ofagglomeration.
 12. The method of claim 11 wherein the raw materialscomprise one or more of whole grain corn meal, rice, whole grain flour,rice pea, brown rice, wheat, whole wheat, pea, black bean, pinto bean,potato, and other grain legumes or tubers.
 13. The method of claim 11wherein the raw materials comprise corn meal.
 14. The method of claim 8comprising the step of expanding the raw materials within the dieassembly into a food product comprising a bulk density of between 3.0and 6.0 lbs./cu ft.
 15. The method of claim 8 wherein the food productcomprises a final moisture content of less than about 3%.
 16. The methodof claim 8 wherein the temperature at the stator head is between about260° F. to about 320° F.
 17. A product made by the method of claim 8.18. An extruded collet snack food product comprising: a base portionconsisting of non-agglomerated food substances, said non-agglomeratedfood substances comprising a first food material; a bulk density rangingfrom about 3.0 to about 6.0 lbs./cu ft.; and a moisture content of lessthan about 3%, wherein the extruded collet snack food product is made bythe rotary head extruder of claim
 1. 19. The extruded collet snack foodproduct of claim 18 wherein the non-agglomerated food substancescomprise a second food material unlike the first food material.
 20. Theextruded collet snack food product of claim 18 wherein the first foodmaterial comprises yellow corn meal or whole grain corn meal.
 21. Theextruded collet snack food product of claim 19 wherein the first foodmaterial comprises yellow corn meal and the second food materialcomprises whole grain corn meal.
 22. The extruded collet snack foodproduct of claim 19 wherein the non-agglomerated food substancescomprise a third food material unlike the first and second foodmaterials.
 23. The extruded collet snack food product of claim 19wherein the non-agglomerated food substances comprise one or more of:cereal flour, cornmeal, and legume flour.
 24. The extruded collet snackfood product of claim 18 wherein the non-agglomerated food substancescomprise milled or ground components.